Enameling furnace and method of preparing the same



Nov. 8, 1927.

F. W. MANKER ENAMELING FURNAGE AND METHOD oF PREPARNG THE SAME Filed Feb.' s, 19'26 2 Sheets-Sheet 1 MW/M .Patented Nov. 8, 1927.

UNITED sraTEs PATENT oFFicE.

FOBEST W. MAN F JACKSON HEIGHTS, NEW YORK, ASSIGNOR TO SURFACE COM- BUSTION COMPANY, 0F NEW YORK, N. Y., 'A CORPORATION 0F NEW YORK.

` `nivAnnuaire runNAo'E Ann METHOD or rnnranme 'ran saine.

#Application eld February j, 1926. Serial No. 85,649.

This invention relates to improvements in -furnaces and a method of' preparing the same and more particularly to furnaces in which bath tubs may be heated during the enameling operation.

. rlhe most common type of furnace-for use in enameling bath tubs is the muiile type furnace adapted lto be heated by such fuels as coal, oil or producer gas. The Inutile furnace is, however, expensive to build and to keep in repair though it has the advantage of giving a working chamber atmosphere that is practically free of dust and the like which cause specks and imperfections in the enamel.

rlhe present invention has for its ohjectsI toprovide a furnace for the purpose specied which shall be of the direct-fired type and in which gaseous fuel may be utilized for heating p'urposesgwhich shall'be ecovide a furnace in which the tubs may be quickly and uniformly' heated without danger of overheating the rims `of the tubs and to-provide a furnace in which the danger of particles falling into the vtub from the 'walls and roof of the furnace shall be reduced to a minimum.

In accordance with the present invention the heating chamber ofthe furnace is formed with side walls which diverge upwardly from the floor of the heating chamber, the angle of inclination ofthe side walls preferably being about the sameas that of the sidewalls ofthe standard conventional type of bath tub. `The -flqor "of the `heating chamber is a relatively -thin false floor beneath which gaseousfuel is adapted to be burned to heat the floor whereby portions of the` tub may be heated by heatA radiating from the floor. This licor is provided with openings along the side walls `ofthe lchamber which'openings serve as passages through which the combustion gases may pass upwardly into the heating. chamber for circulation about theA tub to further -heat the same.

The'roof of the heating chamber is preferably of arched form land is provided with a longitudinall 5 extending row of openings through whic i the combusted gases may pass out ofthe heating chamber. Associated with the vopenings are means for controlling the relative sides thereof in order toinsure the proper circulation of the gases 'at the ends of'the heating chamber and to maintain a uniform temperature within the same.

The heating chamber is fired by gaseous fuel introduced below the floor of-the heating chamber. To enable utilization of the residual heat in the gases leaving the heating chamber through the roof openings, a recuperator is mounted on the top of the furnace whereby/the hot gases leaving the heating chamber pass directly to the recuperator to preheat thc air which is to be mixed with the fuel gas before vits introduction into the combustion space beneath the oor of the heating chamber.

To prevent particles of brick and the like from breaking away from the roof and walls` of the heating chamber, and falling into the enamel on the tub, the interior surface of the chamber is glazed with a .suitable refractory glaze.

The 'above and other various novel features of the invention will more fully appear from the detailed description taken in connection with the yaccompanying drawings forming part of this specification and will be particularly set forth in the appended claims.

Referrin to the drawings: f

Fig. l 1s a vertical transverse section through the improved furnace and showing the preferred construction thereof;

Fig. 2 is a horizontal section through the furnace on a reduced scale, the floor of the heating chamber being shown in plan, and

F ig. `l", .is a vertical section through'the furnace on the same scale as Fig. 2.

The base on which the furnacerests is indicated at 10; the exterior side walls of the' furnace at 12 and the end walls thereof at 14:. One of theend walls is provided with a door opening 16 through which the work to be heated may be entered into the furnace and removed therefrom. Associated with the door opening is a door 18 which is pref` erably of the vertically movabletype, suitable upright guides 20 bein `provided in .I the wall for confining the 4The weight of the door is balanced by suitoor in place.'

able counter-weights 22 located at theopposite endy of the furnace `and which are connected to the door byv suitable cables `24: which pass over the top of the furnace and around sultable pulleys -26 mounted on said top. The door is opened and closed hy nears of a 'Suitable not?? .28 disposed in, a.

- an arched roof 32, a relatively thin flat floor 34 which is of less width than the width of the roof of the chamber, and upwardly diverging side walls 36. I

The Hoor 34 is a false floor which is supported in spaced relation with respect to the.

base of the furnace by means of a series of pillars 38. The floor is provided with a serles of openings 40 which extend along the foot of each of the inclined side walls 36, the openings along one inclined wallbeing in staggered relation with respect to the open, ings along the other inclined wall for a purpose that will presently appear. The floor openings 40 serve as passages through which hot gases may enter the heating chamber,

, groups of burners 50' arranged in the side 554 these hot gases constituting the products of combustion formed by the burning of fuel beneath the floor of the heating chamber as will be presently explained.

The arched roof 32 of the heating chamber is provided with a row of openings 42 through which the gases entering into the furnace may leave the same. These roof openings are preferably located in a line which extends longitudinally .of the roof along the middle thereof. In order to control the outiow of the gases and the circulation thereof within the heating chamber there is preferably associated With the roof openings movable tiles 44 by means of which the size of the openings can be varied .or by means of which some of the openings can be closed. vThe roof openings 42 open into a longitudinally extending passage or mani? fold 46 from whence the gases flow toal recuperator generally 'indicated-at 48.

Gaseous fuel is introduced and Iburned beneath the floor of the heating chamber whereby heat will be radiated from the ioor to the tub thereabove. preferably introduced into the combustion space beneath the floor by means of two walls of the furnace.- The two groups of burners are shown as arranged in staggered relation, see Fig. 2, the individual burners being so disposed that there is ailoor opening 40 between any two-adjacent burners.

By arranging the burners as indicated thev burning gases from one group of burners tend to flow out `through the openings 40 at the far side of the combustion chamber and the burning gases from the other group tend toow out throughfthe other group of open- The fuel is ings 40 as will now be readily understood.

owever, the burning gases are not confined to any particular path of How but may flow freelyl beneath the entire floor inasmuch as the floor is supported on pillars 38 air from pipes 58 leading from the recuperator 48, the air to be heated in the recuperator being entered thereinto by way of a conduit 60 at the top of the recuperator.

The recuperator is preferably composed of a pluralit of metal conduits 62 so arranged so as to orm a circuitous path for the air to be heated and to provide passages between andv around` the same for the hot gaseswhich pass out of the heating chamber on their way to the stack (not shown The floor of the heating c amber is provided with a pair of raised tracks 64 on which the tub to be heated may be supported in spaced relation to the floor during the enameling operation. The bathtub to be heated is shown in dotted lines in Fig. 1 and is indicated by reference letter B. It will be noted that the heating chamber is considerably wider than the bath tub thus insuring a uniform temperature around the entire tub.

By arranging the side walls of the heating chamber so that they shall bev substantially parallel with the adjacent side walls ofthe tub, the amount of heat radiated to the tub side walls from the chamber walls is substantially uniform through the entire areaof the tub side walls. Moreover, by inclining Ythe chamberside walls as stated, the hot gases entering the heating chamber through the floor ports have a free unrestricted flow ath between the adjacent chamber wall an tub wall,-a feature which Serves to prevent concentration of the hot gases along the rolled over edge of the tub with consequent overheating of such edge. Another important result effected by having the chamber side walls inclined is that the hot gases entering the chamber are more readily deflected downwardly into the tub upon striking the arched roof. Thorough circulation of the hot gases is therefore1 obtained with resultant unie, formity of temperature throughout the entire chamber. v

One seriousdrawbackto `direct-fired enam-v eling furnaces as heretofore proposed has been, that particles of brick and the like would become dislodged from thechamber v roof and side walls and fall into tub with consequent blemishing of the enamel. y In the resent invention this diiculty is overcome y glazing the roof and side walls of the heating chamber witha suitable glaze before the furnace is put into use for enameling operations. The glazed-walls of the chamber incidentally serve to permit better re" ber door, the door as previously explained is "o f. yand adjacent to, said walls,

arranged to open downwardly instead of upwardly as is customary in ordinary furnace construction.

The 'fuel gas used in firing the furnace is preferablyfthe same kind of as as is supplied for household use incities. This gas is clean and is admirably adapted for use in firing the furnace of the present invention. The as-air mixture should be such that more izhan sufficient air for theoretically complete combustion is supplied. By supplyingv an excess of air all tendency for soot to form is entirely obviated.-

The present invention offers a furnace which may be built and maintained atv a minimum of expense as compared with'enameling furnaces now in use and enables the. production of enameled bath tubs of first quality at a minimum cost. Furthermore by providing the heating chamber with inclined side walls and heating the chamber in the manner indicated it has been found that the enamel operation can be completed with less rehandling of the bath tub than is found lnecessary in the conventional type of enamel furnaces.y |lhe improved furnace has the further advantage of being easily operatedon account of the fact that fuel for heating the same has a substantially constant composition at all times.

What is claimed is:

l1. In a furnace for enameling bath tubs, the combination of a heating chamber having its side walls inclined upwardly andeutwardly from the ioor thereof, the oor having a series of ports extending lengthwise of and adjacent to said walls, and means for supplging hot gases to the interior4 of said cham er through said floor ports.

2. .In a furnace for enameling bath tubs, the combination of a heating chamber having its side walls inclined upwardly and outr wardly from the floor thereof, the floor having aseries of ports extending lengthwise of fand adjacent to said walls, means for heating said oor from beneath, and means for sup- Eileying hot gases to the-interior of said chamr throughjsaid floor ports;-` 3. In a furnace for enameling bathtubs, the combination of a heating chamber havingits sidewalls inclined upwardly and outwardly from the oor'thereof, the Hooi' having a series of ports extending. lengthwise means for arched roof extending betwee'n said si suppl ing hot gases to the interior of said cham er through said oor orts, and the roof of the heating chamber avinr a` series of ports extending lengthwise of the chamber midway the sidewalls thereof and through which roof ports the hot gases entered 1nto the heating chamber may leave the chamber.

4f. In a furnace for enameling bath tubs, the combination of a heating chamber having its side walls inclined upwardl and outwardly from the door thereof, a p uralit of combustion chambers of which said of ports extending lengthwise of and adjacent to said side walls and through which oor' constitutes the roof, said floor having a series eci floor ports the combusted gases formedv in the combustion chambers may ow into the heating chambers.

5. In a furnace for enameling bath tubs,

the combination of a heating chamber having its side walls inclined upwardl and outwardly from the floor thereof, a p urality of combustion chambers of which said iioor constitutes the roof, said floor having a series of ports extending lengthwise of and adjacent to said side walls and through which licor ports the hotV ro'ducts of combustion formed in the comlbustion chambers may flow into the heating chamber, and the roof of the heating chamber having a row of ports extending from one end of the chamber to the other through which the combusion products entered into the chamber'may eave. Y

6. In a furnace for enameling bath tubs, a heatin chamber having upwardly diverging si e walls, a false door in said chamber, said floor having openings extending along said side walls, means for burning fluid fuel beneath. said ioor for heating thelatter throughout its area, said floor openin s serv- 'ing as passages for the entrance of t e com-- bustion gases into the heating chamber, an

walls and having a row of o enings extendin lengthwise thereof mi way the side wa and through which o nings the gases ma leave the chambery/an means for regulatmg the size of the individual roof openthe door o enings, said openings serving as 4passages trough which `the combustion gases may enter said chamber, and means in the roof of the Achamber for regulating the outdw of said gases from the said chamber.

8. In a furnace for lenameling bathl tubs,v

a. heating chamber adapted to be heated by the 0f cembustible gases therebeof a furnace for enameling operations which comprises applying a glaze to the interior Walls of the furnace before the furnace is 10 used for enameling operations.

In testimony whereof I aix my signature.

FORREST W. MANKER. 

